Subject: Returned mail: see transcript for details

From: Mail Delivery Subsystem <[email-masked]>
Date: Thu, 9 Aug 2007 11:42:08 -0400 (EDT)

The original message was received at Thu, 9 Aug 2007 11:42:08 -0400 (EDT)
from 

   ----- The following addresses had permanent fatal errors -----
nouser.error
    (reason: 550 5.1.1 User unknown)

   ----- Transcript of session follows -----
550 5.1.1 nouser.error... User unknown